1. Field
One or more embodiments of the present invention relate to a headset device, and more particularly, to a headset device and a method measuring a biosignal while a user is working out.
2. Description of the Related Art
Various types of sensors are used in order to measure biosignals such as an electrocardiogram or pulse. For example, an electrode sensor may be used for sensing a change of a current, or photo plethysmography (PPG) may be used for sensing a change of light. Such sensors may be installed in articles of clothing such as gloves, hats, and accessories. Sensors may allow the measurement in real time of a change in the physical condition of a user who is wearing the clothing. For example, a headset device including an earphone or headphones may be used to measure a change in the physical condition of a user who is exercising. A headset device is any device that may be placed on the head of a user, and may be used for easy measurement of a biosignal. Also, a headset device may provide music while measuring the biosignal. Accordingly, measurements may be performed with minimal interference to the user and an application range may be relatively broad.
In order to improve the sensitivity of a sensor and obtain reliable results, a user whose biosignal is being measured should remain relatively still. When the user is moving or exercising, any biosignal measured may be inaccurate. The inaccuracy may result from the movement of the sensor with respect to the user's body that results from jarring and movement during exercise. In addition, the change may be unpredictably irregular. Particularly, since the head is an area having a wide range of movement, any measurement made in the head area may be highly distorted during exercise.
Any distortion caused by user movement may vary depending on the direction of the movement in relation to a human body. As an example, a headset device may be more highly influenced by a movement in a perpendicular direction than a movement in a length-wise direction. The length-wise direction may indicate a direction parallel to the surface of the skin making contact with the sensor. The perpendicular, or transverse, direction may indicate a direction perpendicular to the surface of the skin making contact with the sensor, i.e. perpendicular to the length-wise direction.